Heretofore, salt complexes of methylenedianiline (MDA) have been utilized to cure various urethane prepolymers generally at elevated temperatures in the presence of various compounds or catalysts. For example, U.S. Pat. No. 3,888,831 to Kogon relates to curing of amine-curable polymers or prepolymers utilizing a salt complex of methylenedianiline in association with a polar compound such as an ester, a ketone, an ether, a halogenated hydrocarbon, a tertiary amine, a sulfone, a sulfoxide, or a sulfide.
U.S. Pat. No. 4,046,743 to Schonfeld relates to the use of MDA as a curing agent of amine curable polymers or prepolymers in the presence of a high dielectric constant catalytic compound such as tributyl phosphate.
U.S. Pat. No. 4,517,331 to Parker relates to a prepolymer of a polypropylene ether glycol, a sufficient amount of an organic polyisocyanate and a complex of MDA in the presence of a pseudocrown ether containing various radicals.
U.S. Pat. No. 4,463,155 to Kibler relates to a polyether polyurethane elastomer prepared from a polyether prepolymer, a polyether diol such as polytetrahydrofuran diol, and a curing agent such as an amine curing agent or a diol curing agent.